Re: [PATCH v6 2/4] media: venus: pm_helpers: use opp-table for the frequency

[Bryan O'Donoghue]

On 09/01/2025 13:05, Konrad Dybcio wrote:
> On 2.01.2025 6:38 AM, Renjiang Han wrote:
> > On 12/23/2024 10:17 PM, Konrad Dybcio wrote:
> > > On 19.12.2024 6:41 AM, Renjiang Han wrote:
> > > > The frequency value in the opp-table in the device tree and the freq_tbl
> > > > in the driver are the same.
> > > >
> > > > Therefore, update pm_helpers.c to use the opp-table for frequency values
> > > > for the v4 core.
> > > > If getting data from the opp table fails, fall back to using the frequency
> > > > table.
> > > >
> > > > Signed-off-by: Renjiang Han<quic_renjiang@xxxxxxxxxxx>
> > > > ---
> > > >    drivers/media/platform/qcom/venus/pm_helpers.c | 53 +++++++++++++++++++-------
> > > >    1 file changed, 39 insertions(+), 14 deletions(-)
> > > >
> > > > diff --git a/drivers/media/platform/qcom/venus/pm_helpers.c b/drivers/media/platform/qcom/venus/pm_helpers.c
> > > > index 33a5a659c0ada0ca97eebb5522c5f349f95c49c7..b61c0ad152878870b7223efa274e137d3636433b 100644
> > > > --- a/drivers/media/platform/qcom/venus/pm_helpers.c
> > > > +++ b/drivers/media/platform/qcom/venus/pm_helpers.c
> > > > @@ -43,14 +43,20 @@ static int core_clks_enable(struct venus_core *core)
> > > >        const struct venus_resources *res = core->res;
> > > >        const struct freq_tbl *freq_tbl = core->res->freq_tbl;
> > > >        unsigned int freq_tbl_size = core->res->freq_tbl_size;
> > > > +    struct device *dev = core->dev;
> > > > +    struct dev_pm_opp *opp;
> > > >        unsigned long freq;
> > > >        unsigned int i;
> > > >        int ret;
> > > >    -    if (!freq_tbl)
> > > > -        return -EINVAL;
> > > > -
> > > > -    freq = freq_tbl[freq_tbl_size - 1].freq;
> > > > +    opp = dev_pm_opp_find_freq_ceil(dev, &freq);
> > > > +    if (IS_ERR(opp)) {
> > > > +        if (!freq_tbl)
> > > > +            return -EINVAL;
> > > > +        freq = freq_tbl[freq_tbl_size - 1].freq;
> > > > +    } else {
> > > > +        dev_pm_opp_put(opp);
> > > > +    }
> > > I'm not super convinced how this could have ever worked without
> > > scaling voltage levels, by the way. Perhaps this will squash some
> > > random bugs :|
> > >
> > > Konrad
> >   Thanks for your comment.
> >   The default value of freq is 0, and then dev_pm_opp_find_freq_ceil is
> >   used to match freq to the maximum value in opp-table that is close to
> >   0. The frequency values ​​in opp-table and freq_tbl are the same, and
> >   dev_pm_opp_find_freq_ceil is used to assign the minimum value in
> >   opp-table to freq. So the logic is the same as before. I'm not sure if
> >   I've answered your concern.
>
> We talked offline, but for the record: my concern here was about
> clk_set_rate() not scaling RPM/h voltage corners, which this patch
> fixes
>
> Konrad

Konrad is this an RB from you, do you have any other concerns with this 
code ?

Dikshita, Vikash ?

I'll give it a test myself ASAP but any other comments or R/B would be 
helpful.

---
bod